It's easy to know if you are rushing because things start to feel sore. Skin is extremely tough stuff so you aren't going to tear yourself by mistake, so don't worry about that. I mean a bit of soreness is to be expected, but if you're so sore the next day that you can't put the ring back in you know you've over done it. Petroleum jelly works well for easing soreness though.
Hi, today I've been told that I could have a soft phimosis. The other guy have recommended to me to retract the skin and use oil to increase the elasticity of my foreskin. I was looking for exercices but this link is not working. Do you have it?
I do not I'm afraid but there is a subreddit (on Reddit) called phimosis that is dedicated to the methods used to fix it. I'm sure if you just look at a post one of the mods there has replied to you'll see their big list of links to the kind of thing you're after. If not just ask and I'm someone will post them for you.